I didn't read the study (just the abstract, which sounds silly). In general I am skeptical of research that reduces human sexuality to presence or absence of certain chemical compounds (as if you were studying groups of lemurs). Moreover, studies of this type, with such a small sample size, on such a strange and obscure human group (Harvard Business School students,...), tells us nothing about the interesting and dynamic nature of human sexuality.

Of course we know that testosterone and oestrogen etc play a role in promoting sexual behaviour in pretty much all vertebrates. But when we discuss human sexuality, and whether or not someone choses to engage in a "committed" or "uncommitted" relationship (or however you classify it - which is in and of itself a non-trivial problem), you cannot extract away sociocultural factors (what does society deem acceptable/unacceptable?), socioeconomic factors (resources, stability), sociopolitical factors (class, race, gender identity) etc., not to mention factors that most scientists always totally forget related to individual self-reflection (what type of relationship(s) makes me comfortable/happy/fulfilled?), symbolic imagination (what types of relationship(s) do I want to engage in in the future?), etc.

Basically what I am trying to say is that the types of relationships we engage in and why is a very complex topic that requires far more nuance and sophistication than this study would allow with a binary logic and a reduction of human behaviour to hormones. Maybe varying testosterone levels can lead to predictions of "commitment", or maybe they can't. But my hunch is that the higher social, cultural, political, economic, historical affects are much larger. I know that when I think about my own sexual behaviour, the level of testosterone doesn't have so much to say about whether I am in a committed relationship or not, it has much more to do with higher phenomenological and relational complexities.